OAuth2 callback for data source authorization

OAuth2 callback endpoint for completing data source authorization.

This endpoint is called by OAuth2 providers after user authorization. It exchanges the authorization code for access tokens and stores them securely for the data source.

Args: state: OAuth2 state parameter used for CSRF protection code: Authorization code from the OAuth2 provider error: OAuth2 error code if authorization was denied or failed error_description: Human-readable description of the error

Returns: Redirect to the data source details page on success

Raises: OAuth2TokenExchangeError: When OAuth2 provider returns an error InvalidStateError: When state parameter is invalid or expired